Question

Ali and billy ran around a race track. How many more metres did Ali ran than billy in one lap? (Find perimeter)

Answer 1

Ali ran 25.13 m more than bily

Explanation:

From the diagram, we can see that bully runs with the inner track line while Ali runs with the outer track line.

Thus;

Diameter of inner semi circle = 20 m

Diameter of outer semi circle = 20 + 4 + 4 = 28 m

Perimeter of inner semi circle = πD/2 = 10π

Perimeter of outer semi circle = πD/2 = 14π

Now, perimeter of Billy = 80 + 80 + 10π + 10π = 222.83 m

Perimeter of Ali = 80 + 80 + 14π + 14π = 247.96 m

Thus, in one lap, difference in distance between Ali and billy = 247.96 - 222.83 = 25.13 m